Just when we thought we knew it all, we learn that we really know very little about certain pieces of equipment in our shops. Take a minute to review this glossary of terms, courtesy of Ingersoll Rand, as they apply to compressors.
Full load – do you know what this means? In short, this is about air compressor operation at full speed with a fully open inlet and discharge, delivering a maximum air flow.

How about an aftercooler? This is a heat exchanger used for cooling air that is discharged from a compressor. The resulting condensate may be removed by a moisture separator following the aftercooler.

Next up, the air dryer. This is a device that removes moisture from compressed air. It is typically accomplished by cooling the air through a refrigerator or desiccant bed. So what’s a desiccant? It’s a material having a large proportion of surface pores, capable of attracting and removing water vapor from the air.

What about an automatic sequencer? This device operates compressors in sequence according to a programmed schedule. Next, let’s look at capacity. This is the amount of air flow delivered under specific conditions, usually expressed in cubic feet per minute (CFM).

As for dew point, a quick definition: this has to do with the point at which temperature in the air will begin to condense if the air is cooled at constant pressure. At this point, the relative humidity is 100%.

What’s brake horsepower? This is horsepower delivered to the output shaft of a motor or engine, or the horsepower required at the compressor shaft to perform work. And intercooling? This is nothing more than the removal of heat from air or gas between compressor stages.

A modulating control is a system that adapts to varying demand by throttling the compressor inlet proportionally to the demand. Do you know the function of a load/unload control? This is a control method that allows the compressor to run at full-load or no-load while the driver remains at constant speed.

How about pressure range? In a compressor, this has to do with the difference between minimum and maximum pressures for an air compressor. It is also called cut in/cut out or load/no load pressure range.

There’s a lot more going on inside your compressor; this is only the beginning. Ingersoll Rand supplies this partial glossary, plus much more information. If you have further questions, check out the terms at www.buy-air-compressor.com/glossary.php.